We report a development of a multi-color simultaneous camera for the 188cm telescope at Okayama Astrophysical Observatory in Japan .
The instrument , named MuSCAT , has a capability of 3-color simultaneous imaging in optical wavelength where CCDs are sensitive .
MuSCAT is equipped with three 1024 \times 1024 pixel CCDs , which can be controlled independently .
The three CCDs detect lights in g ^ { \prime } _ { 2 } ( 400–550 nm ) , r ^ { \prime } _ { 2 } ( 550–700 nm ) , and z _ { s, 2 } ( 820–920 nm ) bands using Astrodon Photometrics Generation 2 Sloan filters .
The field of view of MuSCAT is 6.1 \times 6.1 arcmin ^ { 2 } with the pixel scale of 0.358 arcsec per pixel .
The principal purpose of MuSCAT is to perform high precision multi-color transit photometry .
For the purpose , MuSCAT has a capability of self autoguiding which enables to fix positions of stellar images within \sim 1 pix .
We demonstrate relative photometric precisions of 0.101 % , 0.074 % , and 0.076 % in g ^ { \prime } _ { 2 } , r ^ { \prime } _ { 2 } , and z _ { s, 2 } bands , respectively , for GJ436 ( magnitudes in g ^ { \prime } =11.81 , r ^ { \prime } =10.08 , and z ^ { \prime } =8.66 ) with 30 s exposures .
The achieved precisions meet our objective , and the instrument is ready for operation .